Automatic power adjustment system for introductory use of a vibrating device on a human body

ABSTRACT

Driving power for a vibrating device is provided at less than full level when the device is initially used. Power is gradually increased in successive steps after a selected number of uses in each step until full power is achieved. Also, a battery-energized driving signal for a vibrating device has a selected characteristic, such as duty cycle, which is set initially at less than an optimum value, when the battery is at full strength. As the battery discharges, the selected characteristic is adjusted toward optimum so as to compensate for reduction in the battery voltage and ensure full power output.

TECHNICAL FIELD

This invention relates generally to vibrating devices which are used ona human body, such as a toothbrush, and more specifically concerns asystem for gradually increasing power to the device from a lower,introductory power level when the device is first used, to a full powerlevel, over a selected interval of time.

BACKGROUND OF THE INVENTION

The invention described herein concerns the operation of vibratingdevices which are used on the human body, including specifically avibrating toothbrush. It should be understood, however, that the presentinvention is not limited to a vibrating toothbrush per se.

With some vibrating devices, including specifically some vibratingtoothbrushes, the initial physical sensation can be unpleasant, evenintolerable. Some users are particularly sensitive, at least initially,to such vibrations, and hence in some cases such users limit the use ofthe device, and in other cases stop use of the device altogether.

Among various attempts to solve this problem, there are some deviceswhich permit the user to adjust the vibrations to a tolerable level.However, such an approach is often unsatisfactory over the long run,since after a while the user will often fail to remember that the deviceis not at full power; also, there may be a reluctance on the part of theuser to increase the vibration of the device beyond a certain point,even though it is important to do so for maximum effect. At less thanfull power, the effectiveness of the device is certainly reduced,sometimes substantially. Hence, it is very desirable for such a deviceto operate at full power, in order to provide effective and desiredresults.

In another approach, a mechanical device is positioned within theapparatus, at a selected location, to restrict the vibrations of thedevice. After a certain period of time, the user will remove themechanical restriction and permit the apparatus to vibrate at fullpower. However, again, the user may fail to remember that the apparatusis being operated in a lower vibration mode, and/or may be reluctant toremove the restrictor and change to full power/vibrations.

Again, however, it is quite important to operate the device at fullpower, in order to obtain the expected effects.

DISCLOSURE OF THE INVENTION

A first aspect of the present invention concerns a system for graduallyincreasing power to a vibrating device used on the human body,comprising: means for providing driving power, such as by a motor, to avibrating device, such as a toothbrush, in response to a driving signal;means for providing less than full driving power to the vibrating deviceat a first selected point in time, such as when the device is firstused; and means for increasing the power in successive steps in responseto selected successive uses of the device by the user, untilsubstantially full power is achieved.

A second aspect of the present invention concerns a system formaintaining adequate power to a battery-powered vibrating device, whichis to be used on the human body, as battery voltage decreases,comprising: means, energized by a battery, for generating a drivingsignal to operate a vibrating device, such as a toothbrush, wherein aselected characteristic of the driving signal is initially set at lessthan optimum value when the battery is at full voltage; means formonitoring the battery output to determine when the battery hasdischarged to a first selected level; and means for adjusting saidcharacteristic toward an optimum value when the battery voltagedecreases below said first level, so as to maintain normal operation ofthe device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a vibrating toothbrush.

FIG. 2 is a block diagram of the apparatus of the present invention.

FIGS. 3 and 4 are software flowcharts showing the functional operationof the article of FIG. 2.

FIG. 5 is a software flowchart showing the functional operation of avariation of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a battery-powered electric toothbrush which incorporatesthe present invention. Such an electric toothbrush can be designed toproduce various brushing actions, including reciprocal (back and forth),side-to-side and rotational, as well as other, more complicated actions.While the present invention will be described in the context of such anelectric toothbrush, it should be understood that the invention is notlimited to a particular type of electric toothbrush, nor is it limitedto a toothbrush per se. It can be used with a variety of vibratingdevices which have an action or effect which is initially uncomfortableto particular individuals. Such devices could include various kinds ofmassage devices, electric shavers and other similar devices.

The electric toothbrush 10 in FIG. 1 includes a handle portion 12 and anelongated arm 14 which extends from an upper portion 16 of thetoothbrush, terminating in a brushhead 18. Arm 14, which can be mountedin various ways within upper portion 16, is driven by a motor 20, whichin turn is actuated by a driver assembly 22, both of which are locatedin handle 12. Driver assembly 22 includes a rechargeable battery and acharging circuit. Motor 20 can take various configurations, includingelectromagnetic, mechanical and/or electromechanical. The principles ofthe present invention are not dependent upon a particular form of motor.

Toothbrush 10 is operated by an on/off button switch 26 which is pushedand released by the operator. When the toothbrush is not in use, it sitsin a charger unit 28, which operates in conjunction with the chargingcircuit in the driver assembly 22 to charge the battery located in thehandle 12. In the toothbrush 10 shown, there is no direct connectionbetween the toothbrush and an exterior source of electrical energy whenthe toothbrush is removed from the charger unit 28 and actually used.

More specifically, U.S. Pat. No. 5,189,751, titled "Vibrating ToothbrushUsing a Magnetic Driver" and assigned to the same assignee as that ofthe present invention, discloses an electromagnetic toothbrush such asbriefly described above. While the motor in that apparatus drives thebrushhead at a frequency in the range of 150-400 Hz, it should beunderstood that the principles of the present invention are not limitedto a particular brushhead frequency; nor are they limited to aparticular range of vibration. The range of vibration, as well as otherparticular operating characteristics of an electromagnetic toothbrush,are disclosed in U.S. Pat. No. 5,378,153, titled "High PerformanceAcoustical Cleaning Apparatus for Teeth. The contents of both the '751and the '153 patents are hereby incorporated by reference.

As indicated above, in an initial use of a vibrating toothbrush such asshown and described above or other vibrating device, the user mayexperience some or even significant discomfort and elect not to continueuse of the toothbrush or to use the toothbrush in such a manner as toobtain few or none of its benefits. The general solution is to graduallytrain the user to accommodate the vibrations of the toothbrush. In thepresent invention, this is accomplished automatically by graduallyincreasing the power to the brushhead, from an initial, relatively lowlevel, in a series of steps over a selected number of uses, beginningwhen the device is used for the first time.

FIG. 2 shows a general block diagram for the operation of the toothbrushshown in FIG. 1, which incorporates the system of the present invention.The battery charging circuit 32 in the handle of the toothbrush ischarged by charger unit 28. The battery charging circuit 32 chargesbattery 36. Battery 36 powers a microcontroller 38 and a motor drivecircuit 40, while the microcontroller controls operation of the motordrive circuit 40. The microcontroller is shut down and turned on by thepush button switch 26. The output of motor drive circuit 40 is a drivesignal which drives motor 20, which is in this case an electromagneticmotor and which in turn vibrates an arm element on which is mounted thebrushhead 18.

In the embodiment shown, microcontroller 38 controls the operation ofthe motor drive circuit 40 and hence the drive signal in such a mannerthat power to the motor 20 is gradually increased. In the embodimentshown, this is accomplished by varying the duty cycle of the drivesignal from the motor drive circuit 40. At full power, the duty cycle ofthe drive signal will be approximately 100%; microcontroller 38 willcontrol motor drive circuit 40 to provide such a drive signal.

In the present invention, however, the microcontroller is programmed sothat upon initial use of the device, by actuation of push button 26, theduty cycle of the motor drive control signal is relatively low,approximately 47%. Other initial power levels are of course acceptable.The microcontroller thereafter increases the power level, by increasingthe duty cycle, in several sequential stages. In the embodiment shown,there are four power levels between the initial power level of 47% dutycycle and the final 100% duty cycle power level, i.e. 52%, 58%, 65% and80%. The first level is used for the initial four uses, with theremaining power levels each being used twice. Of course, the number oflevels, and the number of times each level is repeated (each use), maybe varied.

In the embodiment shown, the minimum amount of time which qualifies fora single use is one minute. If the toothbrush is operated for less thanone minute in a given use, then that particular use is not considered asa use to qualify for the next power level (or an advance of use within apower level) of the training sequence. This feature prevents prematureincrease in power levels.

The user in the embodiment shown also has the option of bypassing thetraining period entirely or any portion thereof to operate the device atfull power. The training sequence also may be re-enabled as many timesas deemed necessary by the user.

In the embodiment shown, the training sequence is enabled/disabled onlywhen the toothbrush is actually in place in charger 28. The presentstatus of the training sequence is changed, i.e. to on from off and viceversa, by depressing the on/off button switch 26 for a period of twoseconds. When the device is switched into its training sequence, thetoothbrush will generate two audible tones (beeps). When the trainingsequence is switched off, a single beep is generated. When the trainingsequence is on, the toothbrush will generate two audible tones wheneverthe user turns the device on, thereby reminding the user that thetraining sequence is still present.

The training sequence is carried out in microcontroller 38. The specificsoftware implementation is shown in FIGS. 3 and 4. At power on/reset 50,which occurs upon initial charge or recharge of the toothbrush battery,the system is initialized, as shown at 52. At this point, if the on/offbutton switch is not depressed, the system basically goes into aquiescent or "sleep" mode so as to draw minimum battery power, as shownat 54. The above three steps occur apart from actual use of the device,i.e. during initial charging or recharging of the toothbrush.

When the user depresses the on/off button switch, as shown at 56, aninitial determination is made by the software at 58 whether or not thehandle, i.e. the toothbrush, is present in the charger unit 28 (FIG. 1).If the toothbrush is in fact in the charger unit 28 and the on/offswitch is not depressed for a full two seconds, as shown at 60, then thetoothbrush again goes into the sleep mode (shut down). If, on the otherhand, when the toothbrush is in the charger unit, the on/off switch isin fact pressed for two seconds, then the status of the trainingsequence of the toothbrush is changed (toggled) to the opposing state(on to off and vice versa), as shown at 62.

When the training sequence is changed, the new state of the trainingsequence is then determined, shown at 64. If the training sequence ison, the toothbrush will generate two beeps, as shown at 66, while if thetraining cycle is off, only one beep will be generated, as shown at 68.In both cases, however, with the handle in the charger unit 28, thetoothbrush will thereafter shut down.

Going back to step 58, if the toothbrush is not in the charger unit 28when the on/off switch is depressed, such as when the device is to beused, the motor drive circuit 40 is turned on at its then existing powerlevel, whatever that is, as shown at 70. The toothbrush is now turned onand operating. The operation of the toothbrush is under the control of atimer; if the on/off switch 26 is not pressed again, the motor drivecircuit 40 remains at its existing power level until the toothbrushturns off. Typically, an electric toothbrush will have an automatictiming feature so that it will turn off automatically after apreselected period of operation, such as two minutes. Such a toothbrushis shown in U.S. Pat. No. 5,554,382, which is assigned to the sameassignee as the present invention. The contents of that application arealso incorporated by reference herein.

During the time that the toothbrush is running (before it is timed out),if the on/off switch 26 is depressed, as shown at 72, then the motordrive circuit 40 is turned off, as shown at 74. The software then cyclesback to step 71 to see if the timer has run out. The timer will havehalted at its less-than-full time and will remain at that time for apreselected interval, and the software will look to see if the on/offswitch is changed back to on during said preselected interval. If so,the timer will pick up the time again at the halt point. This willcontinue until the timer times out. If not, the interval will expire andthe timer will be reset to its original time, i.e. two minutes.

When the timer does time out, the software determines whether thetoothbrush is in the training sequence, as shown at 76. If not, thetoothbrush will shut down; if on the other hand, the toothbrush is inthe training mode, the software determines whether the toothbrush hasrun for one minute, as shown at 78. If the toothbrush has not run forone minute, then it shuts down. If, on the other hand, the toothbrushhas run for at least one minute, then the power level is incremented,changing the duty cycle to the next higher level, as shown at 80, or tothe next cycle for the same power level. If the power level is now at100%, as determined at 82, then the training sequence is turned off, asshown at 84. If the power level is less than 100%, on the other hand,the toothbrush shuts down. The next time the toothbrush is turned on,the motor drive will be at the new power level.

An alternative to the use of duty cycle is changing the frequency of thedriving signal, when the device is a resonant system. The initial drivefrequency will be some selected value off of (removed from) the systemresonant frequency. The several power levels in the training sequencewill have different driving frequencies, with the driving frequencybeing at the system resonant frequency at 100% power level.

In a variation of the present invention, a selected power characteristicof the driving signal from the motor drive circuit (FIG. 2) is varied inorder to ensure that the device operates at a substantially constantpower output during varying operating conditions, in particular thechange in output of a battery over its discharge cycle. In oneembodiment, the duty cycle of the driving signal is varied in responseto the measured battery voltage. In this embodiment, the drive signalwill have a duty cycle which is less than 100%, i.e. 85%, when thebattery voltage is at full strength. The battery voltage is thereaftercontinuously monitored. When the battery voltage decreases to a firstlevel, the duty cycle of the drive signal is increased a selected amountin order to maintain the desired power level to the motor. Thiscontinues until the duty cycle of the drive signal is 100%. Furtherdecline in battery voltage to a "minimum" level, which is a point wherea significant reduction in device effectiveness has occurred, willresult in the operation of the device being shut down. The device cannotbe restarted until the battery is recharged.

In another embodiment of the constant power system, the frequency of thedriving signal from the motor drive circuit is changed to compensate forthe decline in battery voltage, if the device is a resonant system. Insuch a case, the initial drive signal frequency is some selected valueoff of the system resonant frequency. As the battery discharges, thedriving frequency will be gradually changed, bringing it closer to andfinally approximately at the resonant frequency of the system. At thatpoint, when the battery further declines, below a minimum level, thedevice will be shut off.

FIG. 5 shows a software-based implementation of the constant powersystem. As with FIGS. 3 and 4, at power on/reset, the system isinitialized as shown at 92, and then shut down at 94, until the pushbutton on/off switch is activated at 96. At step 98, it is determinedwhether the handle is still in the charge unit; if it is, the softwareshuts down. If not, then the motor drive is turned on at the last dutycycle and/or frequency, as shown at 100.

The battery voltage is then measured, at 102; if the battery voltage isless than a minimum value, at 103, then the unit is shut down. If not,then the duty cycle or the frequency of the drive signal is adjusted, asshown at 104. As successively decreasing voltage levels are reached,further adjustments are made to the drive signal characteristic. This isaccomplished by a predetermined algorithm which establishes thesuccessive battery voltage levels and the resulting value of the drivesignal characteristic.

After the duty cycle/frequency has been adjusted (or not), adetermination is made at 106 as to whether the toothbrush has timed out.If so, then the toothbrush is shut down; if not, then at 110 it isdetermined whether or not the on/off switch has been depressed. If not,then the program loops back to measure the battery voltage, at 102;while if the on/off switch has been pressed, then the motor drive istoggled (changed) to its opposing state, as shown at 112.

Hence, a system has been described for assisting in accommodating asensitive user to the vibrations of a vibrating device. It includes anautomatic training sequence which advances in accordance with apreselected pattern through various levels of power, and hencevibration, from a beginning point to a final full power point. Inaddition, a system has been described which maintains the power level ofa device over the discharge life of the battery powering the device.

Although a preferred embodiment of the invention has been disclosedherein for illustration, it should be understood that various changes,modifications and substitutions may be incorporated in such embodimentwithout departing from the spirit of the invention, which is defined bythe claims as follows:

What is claimed is:
 1. A system for gradually increasing power to avibrating device used on the human body, comprising:means for producingdriving power to a vibrating device in response to a driving signal;means for providing less than full driving power to the vibrating deviceat a first selected point in time; and means for increasing the power insuccessive steps in response to selected successive uses of the deviceby the user, until substantially full power is achieved.
 2. A system ofclaim 1, wherein the selected point in time is the first use of thevibrating device by a particular user.
 3. A system of claim 1, whereinthe power is increased only in response to a use which exceeds aselected amount of time.
 4. A system of claim 1, wherein the vibratingdevice is a toothbrush.
 5. A system of claim 3, including at least threesteps of power increase.
 6. A system of claim 1, including means forincreasing the power by increasing the duty cycle of the driving signalfrom an initial value which is substantially less than 100% to a valuewhich is approximately 100%.
 7. A system of claim 1, wherein thevibrating device is a resonant system having a resonant frequency, andwherein the means for increasing the power includes means for changingthe frequency of the driving signal from an initial value which isremoved from said resonance frequency to a value which is approximatelyequal to the resonant frequency.
 8. A system of claim 1, including meansfor changing the level of driving power to full power at any point inoperation of said system.
 9. An article of claim 1, including meanspermitting initiation and re-initiation by the user of operation of thesystem.